syzbot

INFO: task syz-executor160:4048 blocked for more than 143 seconds.
      Not tainted 5.15.185-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor160 state:D stack:    0 pid: 4048 ppid:  4046 flags:0x0000000d
Call trace:
 __switch_to+0x2f4/0x558 arch/arm64/kernel/process.c:521
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0xe00/0x1c0c kernel/sched/core.c:6376
 schedule+0x11c/0x1c8 kernel/sched/core.c:6459
 schedule_timeout+0xb4/0x2c8 kernel/time/timer.c:1890
 do_wait_for_common+0x1fc/0x35c kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 __flush_work+0x128/0x1bc kernel/workqueue.c:3094
 __cancel_work_timer+0x2ec/0x448 kernel/workqueue.c:3181
 cancel_work_sync+0x24/0x38 kernel/workqueue.c:3217
 p9_conn_destroy net/9p/trans_fd.c:911 [inline]
 p9_fd_close+0x200/0x398 net/9p/trans_fd.c:946
 p9_client_create+0x840/0xd08 net/9p/client.c:1082
 v9fs_session_init+0x18c/0x139c fs/9p/v9fs.c:409
 v9fs_mount+0x88/0x758 fs/9p/vfs_super.c:126
 legacy_get_tree+0xd4/0x16c fs/fs_context.c:611
 vfs_get_tree+0x90/0x274 fs/super.c:1530
 do_new_mount+0x228/0x810 fs/namespace.c:3010
 path_mount+0x5b4/0x1000 fs/namespace.c:3340
 do_mount fs/namespace.c:3353 [inline]
 __do_sys_mount fs/namespace.c:3561 [inline]
 __se_sys_mount fs/namespace.c:3538 [inline]
 __arm64_sys_mount+0x514/0x5e4 fs/namespace.c:3538
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffff8000143311e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
2 locks held by kworker/1:2/1534:
 #0: ffff0000c0020938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283
 #1: ffff800023487c00 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285
2 locks held by getty/3802:
 #0: ffff0000d3766098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
 #1: ffff80001b8002e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x2f0/0xf6c drivers/tty/n_tty.c:2158

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